336 research outputs found
Quantum photon correlations at the single atom level in free space
In this project, we present a novel approach to calculate and engineer the photon correlations emerging from the interference between an input field and the field scattered by an atom in free space. Historically, it has been difficult to observe robust quantum correlations in the total field, as the inefficient atom-light coupling in free space usually causes the scattered field to be small in comparison to the input. To overcome this issue, we propose the use of separate pump and probe beams, where the former effectively enhances the atomic emission to be comparable to the probe. Additionally, we elucidate the physical origin of the non-classical correlations predicted, by studying the transient atomic state after the measurement of a photon
EFECTIVIDAD DE LAS ONDAS DE CHOQUE EN LOS ESPOLONES DEL CALCÁNEO
Introducción: El dolor de talón es un problema muy común en la población que se caracteriza por un dolor intenso en la cara inferior o posterior del talón causado por una irritación y una sobrecarga de estructuras estabilizadoras del pie. Dicho dolor está relacionado con los espolones del calcáneo, que se encuentran en un 50% de los pacientes con dicho dolor, y con la fascitis plantar. Objetivos: Conocer la efectividad clínica de las ondas de choque como tratamiento del espolón del calcáneo en talalgias. Material y métodos: La metodología empleada para la realización de este artículo se ha basado en una búsqueda bibliográfica utilizando las siguientes bases de datos: Pubmed, y PEDro. Se han incluido todos los trabajos encontrados introduciendo una serie de límites: que los artículos se refirieran a la patología sufrida únicamente en humanos y que estuvieran tanto en inglés como en español. Resultados: Se encontró que la evidencia positiva en el tratamiento de los espolones del calcáneo supera a la negativa y que el tamaño del espolón apenas se veía afectado. Conclusiones: Los resultados de esta revisión indican que las ondas de choque son un tratamiento efectivo para disminuir el dolor y la inflamación de la fascia en pacientes con talalgia con un espolón asociado, sin embargo el tamaño del espolón no se ve afectado
Implementing open-source information systems for assessing and managing the seismic vulnerability of historical constructions
Reducing the uncertainty about the structural vulnerability of historical constructions comprises the selection of reasonably generalised approaches in a context of a significant typological variability; the difficulty of performing large-scale assessments with reasonable reliability; and the lack of dedicated infrastructures for efficiently storing, sharing, managing, and updating data – an issue that is even more relevant for small (and often isolated) settlements. This work presents a proposal to set up a geographic database for surveying, calculating and storing the seismic vulnerability index of masonry constructions using an adapted version of the GNDT-II approach.
Some critical steps for setting up Geographical Information System (GIS) databases for storing and managing the fields of a parameter-based vulnerability assessment are presented. Then, some alternatives for distributing the database are introduced, including cloud-based distribution and Transactional Web Feature Service (WFS-T) protocols, even using virtual servers. Additionally, an alternative front-end for accessing data and calculating the vulnerability index of constructions and levels of damage is presented. The main objective is to offer a replicable and feasible workflow to be performed even with reduced infrastructure and computational resources but can be easily connected and associated to a progressively enlarged system based on free and open-source software
Analysis of fracture resistance of tool steels by means of acoustic emission.
The usage of advanced high strength steels (AHSS) in structural automotive components has
been broadened in the past few years to satisfy the strict specifications of the automotive industry.
Besides showing excellent strength to weight rations, AHSS have several limitations due to the high loads required in cold forming and cutting tools, which decrease considerably the tooling performances. Therefore, these important forces of impact provoke unforeseen breakage of the dies. The aim of this research is to study the micromechanical behaviour and fracture mechanisms (nucleation and crack propagation) during fracture of tool steels using the acoustic emission (EA) technique. To do that, bending testing specimens of different tool steels were monitored in order to establish a relationship between AE signals and their mechanical behavior (carbide breakage, cracks emanating from them and crack propagation through the metallic matrix).Postprint (published version
EFFICIENCY OF ORGANIC COMPOST IN THE DEVELOPMENT OF Moringa oleifera LAM. SEEDLINGS
This study aimed to evaluate the efficiency of organic compost produced through composting in the development of Moringa oleifera seedlings. The experiment was carried out in a greenhouse in Feira de Santana- BA, Brazil. The design was randomized blocks (RBD), with seven treatments per block and four replicates. The following treatments were tested: commercial substrate; sand (S); S/organic compost (OC) 80/20; S/OC 60/40; S/OC 40/60; S/OC 20/80; S/OC 0/100. The organic compost was formed by pruning residues and vegetable remains that were not cooked. The addition of organic compost promoted the highest means for the parameters height, number of leaves, height/collar diameter ratio, root dry mass and shoot dry mass. For leaf area, height/shoot dry mass ratio and collar diameter, the proportions of the compost had no influence. Higher means of parameters such as tuberous root length and diameter and tuberous structure dry mass were observed in the commercial substrate, which may indicate stress in seedlings of this treatment. Substrates with a lower proportion of organic compost are more suitable for the production of M. oleifera seedlings
Cable tension estimation by means of vibration response and moving mass technique
Early damage detection on structures plays a very important role for ensuring safety and reliability. This paper provides an efficient method based on wavelet transforms in order to detect and localize damage on structures subjected to moving loads such as beams and bridges. A numerical model based on the experimental test-rig utilized in this study is developed by using a finite element commercial software. Different types of damage on the bridge of the numerical model are simulated and transient analyses are performed by incorporating a load which moves constantly along the beam nodes. Continuous wavelet transform diagrams using the vertical acceleration responses show that damage can be identified and localized even with significant percentages of noise. Nevertheless, the method is improved by filtering the signals, removing the border effects, and calculating the total wavelet energy of the beam from the coefficients along the selected range of scales. Thus, the accumulation of wavelet energy could indicate the presence of damage. Finally, laboratory experiments are conducted to validate this work and a good agreement between numerical and experimental results is obtaine
Acceptability of HIV Vaccine - Efficacy Trials in Drug Users and Sexual Partners of HIV Infected Patients in Barcelona, Spain
Implementing open-source information systems for assessing and managing the seismic vulnerability of historical constructions
The characterisation of the seismic vulnerability of historical constructions represents a complex problem in which the typological variability, the difficulty of performing reliable large-scale assessments and dealing with a large database all play a role. Nevertheless, reducing the uncertainty regarding the structural vulnerability of the existing building stock (mostly for small and/or isolated human settlements) is key for risk assessment and management. The present work proposes a novel approach based on the integration of a series of open-source tools for assembling a vulnerability-oriented database that is linked to a series of external services for increasing its capabilities. The database was implemented in a Geographical Information System (GIS) environment and contains the survey of a seismic vulnerability index for masonry constructions based on an adapted version of the GNDT-II approach. A customised Python-based software for reading, managing and editing the database is herein presented. This program allows the execution of the most typical operations with no assistance from the GIS environment, facilitating user interaction. Furthermore, the calculations regarding the vulnerability index and levels of damage have been implemented in this program. Alternatives for distributing the database are implemented and discussed, such as cloud-based distribution and the use of the Transactional Web Feature Service (WFS-T) protocol for its virtual publishing. The entire framework herein presented is a replicable and feasible workflow that can be set even with reduced infrastructure, allowing a progressive enlargement
Rhythm Rangers:an evaluation of beat synchronisation skills and musical confidence through multiplayer gamification influence
Musical confidence and beat synchronisation skills are explored before and after playing the custom made multiplayer game, Rhythm Rangers. Timing variability is evaluated comparing scores from a repeated baseline test, preand post-game. A qualitative questionnaire assessing musical sophistication, behaviours, and confidence is used for correlation. Participants synchronise claps at quarter-note level to audio loops of varying rhythmic complexity from metronome, to complex syncopated break-beat. The setup comprises bespoke wearable controllers and software integrating multi-sensor microcontrollers (ESP32), a microcomputer (Raspberry Pi), and a visual programming language (Pure Data). Baseline test results indicate better overall beat synchronisation to drum loops compared to a metronome—similar results were found for game scores where the average standard deviation (SD) was highest for the metronome. Average drift variability showed a downward trend for both baseline test loops (metronome and simple drum loop). Total average SD decreased with relation to the amount of rhythmic information in the loops until the complex break-beat. Little correlation between the qualitative data and the participant’s performance during the experiment was found. Dependant samples T-test for the simple drum loop showed a significant effect ( t = −2, 48, p < 0.05). No significant effect for the metronome (t = 0.03, p < 0.05) when comparing the baseline test before and after the game. Participants with least or no improvement found the game most challenging; higher game scores showed the least improvement; less experience with rhythm games showed the most improvement. All participants claimed to have had fun and enjoyed themselves while playing the game
Association between sex differences on foot health related to the quality of life in a sample of sedentary people
[Abstract] Sedentary (sitting) time may produce many anatomical and physiological consequences which are supposedly associated with a decreased quality of life (QoL) related to foot health. Accordingly, this study aimed to analyze the QoL impact on the overall health and the foot health among male and female sedentary people. A total of 312 participants with an age mean of 39.81 ± 15.40 years completed all phases of the study. In addition, self-reported data were registered. The participants' sedentary lifestyle was determined using the European Prospective Investigation into Cancer and Nutrition (EPIC) physical activity questionnaire.
Furthermore, the scores obtained from the Portuguese version of the Foot Health Status Questionnaire were registered. Sedentary people in the equivalent metabolic energy had 301.09 ± 72.22 (min/week). In the first section, values were higher for foot pain and foot function and lower for general foot health and footwear. In the second section, values were higher for general health and vigor and lower for physical activity and social capacity. The differences between the sex groups of the study were statistically significant for footwear (P = 0.008), physical activity (P= 0.002), social capacity (P = 0.001) and vigor (P = 0.001) showing a worst QoL related to foot health in favor of male subjects in comparison with females. The rest of the domains did not show any statistically significant difference (P ≥ .01). The sedentary population evidenced a negative impact on the QoL related to foot health. This problem may be associated with this lifestyle, especially for males.[Resumo] O tempo sedentário (sentado) pode produzir muitas consequências anatômicas e fisiológicas que supostamente estão associadas a uma redução de qualidade de vida (QoL) relacionada à saúde do pé. Por conseguinte, o objetivo deste estudo foi analisar o impacto da QV sobre a saúde geral e a saúde do pé entre pessoas sedentárias masculinas e femininas. Uma amostra de 312 participantes com idade média de 39,81 ± 15,40 anos completou todas as fases do processo de estudo. Além disso, os dados autorrelatados foram registrados. O comportamento sedentário dos informantes foi determinado usando o questionário de prospecção prospectiva de câncer e nutrição (Epic). Além disso, os resultados obtidos com a versão em português do Questionário de Status de Saúde do Pé (PFHSQ) foram registrados. As pessoas sedentárias no equivalente de energia metabólica apresentaram 301,09 ± 72,22 (min/semana). Na primeira seção, os valores foram maiores para a dor no pé e função do pé e diminuíram a saúde e o calçado do pé geral. Na segunda seção, os valores foram maiores para saúde geral e vigor e menores para atividade física e capacidade social. As diferenças entre os grupos sexuais do estudo foram estatisticamente significativas para o calçado (P = 0,008), atividade física (P = 0,002), capacidade social (P = 0,001) e vigor (P = 0,001), mostrando uma pior QV relacionada à saúde do pé a favor dos sujeitos do sexo masculino em relação aos participantes sedentários femininos. O restante dos domínios não apresentou diferença estatisticamente significante (P ≥ 0,01). A população sedentária evidenciou um impacto negativo na QoL relacionada à saúde dos pés. Esse problema pode estar associado a este comportamento, especialmente no sexo masculino
- …